In the formulation of cementitious compositions it is known in the art to use mixtures of different hydraulic cements, as well as other additives such as accelerators and retarders, in order to provide such characteristics of setting times, strengths and volume changes as are needed to meet the exigencies of various specialty applications. Thus, in U.S. Pat. No. 4,769,077 to Crocker, there is provided a fast setting shrinkage compensating cementitious formulation for use in effecting grouting repairs in road surfaces and the like. This formulation comprises a hydraulic cement mixture of a major amount of a Portland cement constituent and a minor amount of an expansive ettringite forming sulfoalumina cement constituent, along with an aggregate and an accelerator. The accelerator component is a polyvalent metal salt of formic acid, specifically an alkaline earth metal formate such as calcium formate. Specific formulations include mixtures of a Type I, Type IP, or Type III with a Type K, Type M, or Type S with weight ratios within the range of 2-3. The cementitious composition is to affect a grouting repair by mixing the dry formulation with water to provide a cementitious slurry having relatively short initial and final Gilmore setting times, 7 and 14 minutes, respectively, and 14 days curing.
U. S. Pat. No. 4,082,561 to Nakagawa et. al. discloses a two component system which can be used to provide a quick-hardening slurry which can be used to provide stopping of underground water flows. The quick-hardening cement slurry involves a mixture of a calcium aluminate in an amount of 10% to 50%, and preferably 20-30%, on a cement basis together with a Portland cement which can be a normal, rapid hardening Portland cement or a pozzolanic cement. In the Nakagawa procedure, the calcium aluminate quick-hardening agent can be added to the already formulated hydraulic cement slurry to provide setting times ranging from several seconds up to as long as ten minutes.
U.S. Pat. No. 3,997,353 to Chervenka et. al. discloses a cementitious material having a particular ratio of portland cement to calcium aluminate and calcium sulfate which is useful in effecting repairs at such sites as highways and airport runways. The preferred ratios in the Chervenka formulation include 50-60 wt. % portland cement, 30-40 wt. % calcium aluminate, and 5-18, and most preferably 7-15 wt. %, calcium sulfate. When hydrated and allowed to set, the formulation provides high strengths in two hours to one day's time. For example, the hydraulic cement might set in about two hours to provide a compressive strength of 1000 psi to about 1500 psi and a strength of at least 3000 psi within 24 hours.
U.S. Pat. No. 4,357,167 to Kellet et. al. discloses a cement based flowable cavity filling material comprising a mixture of cement, clay and water with the cement mixture comprising Portland cement, a 10-75% mixture of calcium aluminate and calcium sulfate based upon the portland cement and a mixture of an inorganic salt and organic or inorganic setting retarder. Examples of suitable Portland cements for use in the Kellet formulation include ordinary Portland cement, rapid hardening Portland cement and sulfate resistant Portland cement. As noted above, clay can also be employed. Two supply lines can be provided to supply the formulation materials to the cavity with one line supplying a slurry containing the cement mixture and the other line a slurry containing the clay and also the inorganic salt.